The first concept we are going to explore for Savor the Science is the Maillard browning reaction. Named after French chemist Louis-Camille Maillard, this reaction is responsible for the rich, delicious, and complex flavors in foods like chocolate, roasted meat, toasted bread, and brown beers. Those are some of my favorite things to put in my mouth, which makes this one of my favorite chemical reactions.
First, let’s back up a bit and talk about browning in general. “Browning” is a broad term that refers to chemical reactions in food in which new flavors are produced. Usually these new molecules cause the food to appear brown, but it’s not the color change that is impressive: it’s the flavors that accompany the change. Instead of existing flavors being intensified (such as in curing or dehydrating), entirely new flavors characteristic of the cooking process come forward to delight your taste buds. A well-known example of this is caramelization, which takes the fairly flavorless (though very sweet) substance known as sugar and converts it into the rich, complex confection known as caramel.
Maillard browning is a similar process, but with different starting material. Whereas caramelization begins with the destruction of sugar at high temperature, the Maillard reaction starts off with the reaction of amino acids (the building blocks of proteins) and a carbohydrate (usually a simple sugar).
These reactions don’t happen spontaneously; a large amount of energy is required to start a Maillard reaction. There is some disagreement about exactly how high the temperature needs to be, but god-among-men Harold McGee says it’s 250F or 120C and above. At these high temperatures, the amino acid begins to react with the carbohydrate, forming a very unstable intermediary structure. This structure then continues to undergo changes and eventually produces a whole new family of molecules. Slapping a steak on the grill produces hundreds of new tasty compounds! These meaty aromas and flavors are usually small rings containing nitrogen, sulfur, and oxygen, in addition to carbon and hydrogen. While most of the flavors possess a generic “roasted” flavor, they can also be described as “oniony,” “grassy,” or “spicy.”
Because such high temperatures are required for Maillard browning, boiled meat (and other foods) will never brown. No matter how high you turn up your burner, water will never get hotter than 100C (unless you mess around with the pressure, but I doubt you are doing that in your home kitchen). As long as water is being used to transfer heat to your food, no Maillard reaction can take place; you simply cannot get it hot enough.
This ties in with why you’ve heard over and over again not to “crowd the pan,” and it’s advice you should follow! If you put too much of a high moisture food into one pan, the moisture will collect and the food will boil or steam, keeping the temperature too low for Maillard browning to occur.
Now that we have a basic understand of Maillard browning and how it forms all of those savory, roasted flavors, let’s create some meaty-tasting molecules of our own. My favorite application for this reaction is the searing of meat; I love a good crust on a pan-seared steak. The recipe below will show you how to make a simple seared steak. Keep in mind that the most important ingredient is HEAT.
You will need:
A heavy-bottomed stainless steel or cast iron pan
A delicious cut of red meat (such as a ribeye)
Vegetable oil or bacon grease
Some wine or red wine vinegar to deglaze the pan
Crushed garlic or prepared horseradish (optional)
1. Open your windows. It might get a little smoky.
2. Take your steak out of the fridge and let it come to room temperature. Pat it dry with paper towels to remove that pesky water.
3. Get your pan HOT. I set my stove (which goes to 11) to around 8 or 9, any higher and my oil starts to burn. The oil should just barely start to smoke and meat should instantly sizzle when it touches the pan.
4. Add enough oil or grease to thinly coat the pan.
5. When you start to see that hint of smoke, salt your meat liberally and gently lay it down in the pan. Do not throw the meat in quickly; you will get splattered with hot grease.
6. DO NOT TOUCH IT. If you move it around you will be interrupting those wonderful Maillard reactions, and nobody wants that.
7. After 3 minutes flip that thang and let it cook, undisturbed, for another 3 minutes. Continue to flip every minute or so until you reach your desired “doneness.” I like mine very rare, so I only do 3 minutes on each side. For medium-rare, flip it back over a couple times to give each side an extra minute.
8. Lower your heat to medium, add a couple of tablespoons of butter and spoon it over the steak continuously for about thirty seconds. Flip and baste the other side.
9. Remove from heat and set aside. Note that beautiful, beautiful crust that YOU MADE with SCIENCE. Let it rest for ten minutes (if you can bear it).
10. Add about half a cup of wine or red wine vinegar to the pan to deglaze. Scrape those tasty little browned bits off the pan with a spoon and let the liquid reduce down into a delicious steak sauce. Add in some crushed garlic or prepared horseradish if you are into that kind of thing.
11. Drizzle the sauce over the steak and be delirious with happiness.
So, that’s Maillard browning. Delicious, amazing Maillard browning.
I hope you enjoyed this first installment of Savor the Science. What food chemistry are you interested in learning about? Let us know in the comments section below!